The present invention relates to a synchronization control of a two motor dual blade glass wiper system for a motor vehicle. In particular, a control is desirable to prevent wiper blades from contact with each other in such a system wherein the wipe patterns of the individual blades overlap to establish an interference zone.
Conventional dual wiper blade systems utilize one motor and shared mechanical linkages which synchronously drive the wiper blades and prevent interferences by way of hardware. More recent dual wiper blade systems have utilized a motor for each blade and some hardware and/or software controlled switching scheme to control each individual motor's cycling and prevent blade contact. Packaging constraints, especially for backglass wiper systems, in many cases will prevent use of mechanically controlled one motor systems. Two motor systems often rely upon moderately intricate software control and position sensing along the continuum of the wipe pattern or rely upon physically different motor assemblies having a multiplicity of integral high voltage/high current switching cam apparatus thus proliferating part numbers and precluding part interchangeability.
Improvements can be made to such prior art wiper systems. For example, software can be simplified if position sensing resolution is limited to predetermined key positions of a wiper blade in a wipe pattern. Two motor drive systems can utilize one motor assembly part number for both motors to eliminate unnecessary duplicity of similarly functioning parts. Further, by utilizing computer based control, high voltage/high current switching functions can be accomplished external to the motor hardware via more robust and better suited switching circuitry.